1. Field of the Invention
The present invention relates to a medical apparatus designed so that an image of a luminous flux from a subject incident on an objective lens is formed on image-pickup means by means of an imaging lens and an image of the subject is picked up by means of the image-pickup means.
2. Description of the Related Art
Modern surgical operations are frequently performed under endoscopic observation. In many cases, rigid endoscopes are used in endoscopic operations. A rigid endoscope has an insertional section substantially in the form of a cylinder. An observation optical system is incorporated in the insertional section, and an image-pickup optical system is located in the proximal end portion of the insertional section. In performing an endoscopic operation, an operator directly holds and manipulates the rigid endoscope, and inserts the insertional section into a body cavity through an orifice in a patient's body surface region. Then, the operator directs an objective lens (one-way screen) of the observation optical system toward an operative region of the subject and observes the operative region through the lens. If any body tissue interferes with the inserted insertional section as the operator directly manipulates the rigid endoscope, the operator can recognize the interference by a feeling in his/her hand that holds the endoscope.
In some cases, moreover, the posture for the endoscopic observation is continuously maintained by fixedly supporting the endoscope by means of a holding apparatus, such as a stand. In general, the endoscope holding apparatus of this type is composed of a plurality of joints that can be shifted alternatively between a fixed state and a rockable state. When the joints are in the rockable state, the operator can freely change the posture of the endoscope. When the joints are in the fixed state, on the other hand, the operator can fixedly support the endoscope in that posture. Typical endoscope holding apparatuses are described in Jpn. Pat. Appln. KOKAI Publication No. 7-227398 and U.S. Pat. No. 5,815,640. Proposed in Jpn. Pat. Appln. KOKAI Publication No. 8-254472, moreover, is an endoscope that is provided with a pressure sensor for detecting external force that acts on its insertional section.